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A230676 Number of 2 X n 0..2 arrays x(i,j) with each element horizontally, diagonally or antidiagonally next to at least one element with value 2-x(i,j). 1
0, 15, 87, 513, 3387, 21933, 141411, 913245, 5898099, 38088477, 245968275, 1588424445, 10257784563, 66243081501, 427786930899, 2762577674301, 17840272397235, 115209545904477, 744004305214611, 4804657476983421 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 5*a(n-1) + 6*a(n-2) + 20*a(n-3) + 12*a(n-4) + 8*a(n-5).

Empirical g.f.: 3*x^2*(5 + 4*x - 4*x^2) / (1 - 5*x - 6*x^2 - 20*x^3 - 12*x^4 - 8*x^5). - Colin Barker, Sep 22 2018

EXAMPLE

Some solutions for n=3:

..0..2..2....0..0..2....1..1..1....0..2..0....0..0..2....0..2..0....2..2..2

..0..0..0....2..2..2....1..2..0....0..2..0....2..2..0....0..1..1....0..0..2

CROSSREFS

Row 2 of A230675.

Sequence in context: A199897 A309922 A302948 * A232070 A219598 A241433

Adjacent sequences:  A230673 A230674 A230675 * A230677 A230678 A230679

KEYWORD

nonn

AUTHOR

R. H. Hardin, Oct 27 2013

STATUS

approved

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Last modified June 19 15:57 EDT 2021. Contains 345144 sequences. (Running on oeis4.)